Contrast Checker
Measure WCAG contrast between two opaque sRGB colors and compare AA and AAA text thresholds.
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How it works
Measure WCAG contrast between two opaque sRGB colors and compare AA and AAA text thresholds. Enter your values or try the example. Run the action, check the result and copy or download it. Your input remains editable after an error.
Example
#000000 + #FFFFFF → 21.00:1
When to use this tool
Check a text-and-background color pair before adding it to a design. This does not audit the whole page.
Supported formats & limits
WCAG 2 text thresholds: AA 4.5:1 normal / 3:1 large; AAA 7:1 normal / 4.5:1 large. Large text means at least 18 pt regular or 14 pt bold. This checks a color pair, not a complete page’s accessibility.
Something isn’t working ↗Good to know
What happens when I change the input?
An edited input needs a new result. Run the action again; previous download links are removed so you cannot mistake an old output for the current one.
Are my files uploaded?
Your files and pasted content are processed in temporary browser memory and are not uploaded for processing. App preferences store only tool IDs, language and theme. There are no accounts, ads or automatic error reports. Closing the page discards your workspace; download results you want to keep. Production pages use Google Analytics for visit statistics; see the Privacy page for details.